Sorry. I'm russian and I am don't know french language. And I am write on english.
"A promissory note is a legal instrument (more particularly, a financial instrument), in which one party (the maker or issuer) promises in writing to pay a determinate sum of money to the other (the payee), either at a fixed or determinable future time or on demand of the payee, under specific terms. If the promissory note is unconditional and readily salable, it is called a negotiable instrument."